Method for preparing a semiconductor structure

1. A method for preparing a semiconductor pattern structure, comprising:

forming a mask stack comprising a first mask and a second mask on a substrate;

forming a plurality of third masks over the mask stack;

forming a patterned layer over the third masks, wherein the patterned layer comprises a plurality of first openings;

removing portions of the second mask through the first openings and through the third masks to form a plurality of second openings, wherein portions of the first mask are exposed through the second openings;

forming a plurality of self-aligned protecting structures in the second openings;

removing portions of the second mask exposed through the third masks to form a plurality of third openings, wherein portions of the first mask are exposed through the third openings;

removing the portions of the first mask exposed through the third openings to form a hybrid hard mask; and

etching the substrate through the hybrid hard mask to form a plurality of recesses.

2. The method of claim 1 , wherein the hybrid hard mask comprises the first mask and the second mask.

3. The method of claim 2 , wherein the hybrid hard mask further comprises at least one self-aligned protecting structure.

4. The method of claim 3 , wherein the first mask form a base for the hybrid hard mask, the at least one self-aligned protecting structure and the second mask are disposed on the first mask, and the at least one self-aligned protecting structure is sandwiched between portions of the second mask.

5. The method of claim 4 , wherein a top surface of the at least one self-aligned protecting structure is coplanar with or higher than a top surface of the second mask.

6. The method of claim 1 , wherein the third masks extend along a first direction, and the first openings extend along a second direction different from the first direction.

7. The method of claim 1 , wherein the forming of the third masks comprises:

forming a plurality of core patterns over the mask stack;

forming a plurality of spacers over sidewalls of each core pattern; and

removing the core patterns to form the third masks.

8. The method of claim 1 , wherein the forming of the patterned layer further comprises:

forming a sacrificial layer over the third masks to form an even surface over the substrate;

forming the patterned layer over the sacrificial layer; and

transferring the first openings into the sacrificial layer.

9. The method of claim 8 , further comprising removing the sacrificial layer prior to the forming of the third openings.

10. The method of claim 1 , further comprising removing portions of the third masks exposed through the first openings.

11. The method of claim 1 , further comprising forming a conductive layer to fill the recesses.

12. The method of claim 1 , further comprising forming a conductive layer to fill the recesses.

13. A method for preparing a semiconductor pattern structure, comprising:

forming a mask stack comprising a first mask and a second mask on a substrate;

forming a plurality of core patterns over the mask stack;

forming a plurality of spacers over sidewalls of each core pattern;

forming a patterned layer over the core patterns and the spacers, wherein the patterned layer comprises a plurality of first openings;

removing portions of the core patterns, portions of the spacers and portions of the second mask exposed through the first openings to form a plurality of second openings, wherein portions of the first mask are exposed through the second openings;

forming a plurality of self-aligned protecting structures in the second openings;

removing the core patterns to form a plurality of third masks exposing portions of the second mask;

removing the portions of the second mask exposed through the third masks and through the self-aligned protecting structures to form a plurality of third openings, wherein portions of the first mask are exposed through the third openings;

removing the portions of the first mask exposed through the third openings to form a hybrid hard mask; and

etching the substrate through the hybrid hard mask to form a plurality of recesses.

14. The method of claim 13 , wherein the hybrid hard mask comprises the first mask and the second mask.

15. The method of claim 14 , wherein the hybrid hard mask further comprises the self-aligned protecting structure.

16. The method of claim 15 , wherein the first mask forms a base for the hybrid hard mask, the self-aligned protecting structure and the second mask are disposed on the first mask, and the self-aligned protecting structure is sandwiched between portions of the second mask.

17. The method of claim 16 , wherein a top surface of the self-aligned protecting structure is coplanar with or higher than a top surface of the second mask.

18. The method of claim 13 , wherein the third masks extend along a first direction, and the first openings extend along a second direction different from the first direction.

19. The method of claim 13 , wherein the forming of the patterned layer further comprises:

forming a sacrificial layer over the core patterns and the spacers to form an even surface over the substrate;

forming the patterned layer over the sacrificial layer; and

transferring the first openings into the sacrificial layer.

20. The method of claim 18 , further comprising removing the sacrificial layer prior to the forming of the third openings.